Hydrocarbon oil conversion



June 16, 1931. J. c: MORRELL EfAL 1,810,673

HYDROCARBON OIL CONVERSION Filed. Feb. 1. 1929 J71 2/6 72 for; llfzlneas: A jmnle a y/ 1, 2! I hfarrerz 171227067267? Patented June 16, 1931 UNITED, STATES. PATENT OFFICE JACQUE C. MORRELL AND WARREN F. FARAGHER, OF CHICAGO, ILLINOIS ASSIGNORS TO UNIVERSAL OIL PRODUCTS COMZEANY, OF CHICAGO, ILLINOIS, A'CORPORA-TION or SOUTH DAKOTA HYDROCARBON OIL CONVERSION Application filed February 1, 1929. Serial No. 336,858.

- profitable yields of commercial products therefrom. v

In the preferred embodiment of the invention, it has been particularly designed to produce maximum yields of lighter hydrocarm bons of .the order of gasoline with necessary yields of good liquid-residue suitable for use as fuel, and minimum yields of coke and in-- condensable gas.

The invention will be described as applied 15 to a process in which oil is heated to a conversion temperature under super-atmospheric pressure, while traversing connected lengths of tubing forming a heating coil, which oil is discharged into an enlarged drum accom- 2 panied by a substantial reduction or release 'in pressure whereby vaporization is effected through the release of latent heat in the reduced pressure drum. Thevapors are dephlegmated, and as a feature of the invention, regulated amounts of the reflux condensate, instead of being returned to the pressure heating coil for further treatment, are separately subjected to those conditions of temperature and pressure which are most suitable for that particular reflux, after which said reheated reflux is discharged into the reduced pressure flashing drum. 7

There are a number of advantages accruing to the use of the present invention, among which may be cited the production of a good liquid residue whichmay be withdrawn from the reduced pressure flashing drum, the increased yield of gasoline, conditions of cracking most suited to the particular materials undergoing-conversion, and the conversion of all products suitable for making gasoline.

Other objects and advantages of theinvention will be brought out more in detail in the following description.

'agrammatic side elevational view of apparatus in which the invention may be carried out.

Referring more in detail to the drawing,

1 designates a charging stock inlet line in 'a conventional type fractionatin The'single figure of the drawing is a di-* which may be interposed the pump 2-aud valve 3. The line 1 merges with the direct feed'line 4', controlled by valve 5, for feeding the oil to the heating coil 6 mounted in a furnace 7 of conventionaltype. The oil being passed through the heating coil 6 is raised to a conversion temperature under suitable super-atmospheric pressure, in a conventional manner. The particular conditions of temperature and pressure suitable fora particular oil are within the purview of those skilled in this particular art.

The heated oil leaving the coil 6 passes by way of transfer line 8, in which may be interposedthe pressure reducing valve 9, to an enlarged drum 10. The drum 10, in the present vinstance functions as a flash chamber, that is, alarge portion of the heated oil discharging through the transfer line 8 into the chamber- 10 vaporizes due, to reduction in pressure through the manipulation of the pressure reducing valve 9. Such pressure reduction causes a large amount of vaporization to take place due to the latent heat contained in said verted fractions. Vapors remaining incon- .densed after passage through thedephlegmator 13 may be removed through the vapor outlet line 14 and introduced into the bottom of v tower 15, wherein they are fractionated. The vapors remaining uncondensed after passage through the fractionating tower may be removed through the vapor outlet line 16, condensed incondenser coil 17, and collected as liquid distillate in the receiver 18, which receiver is provided with incondensable gas release line 19, controlled by valve 20, and liquiddraw-oif line 21, controlled by valve 22.

Reflux collecting in the dephlegmator 13 may be withdrawn through the line 23, in which may be interposed valve 24 and pump 25. The line 23 merges with the direct feed line 4 and alsowith the line '26, in which may be interposed the valve 27. Line 26 merges with a continuation 28, in which may be interposed the valve 29. The arrangement is such that all or any regulated portion of 5 said reflux passing down through the line 23 may be diverted into the lines 26 and 28 for a purpose to be later described.

We have described an operation in which the charging stock being introduced through the line 1 is charged through the direct feed line 4 to the coil 6. The invention contemplates that all or any regulated portion of the raw oil fed in the line 1 may be diverted into the line 30, controlled by valve 31, and introduced into the upper part of the dephlegmator 13 for use as a cooling medium to condense the insufliciently converted fractions of vapors ascending therethrough, as heretofore described. At this point, it may be well to point out that the raw oil introduced through line 30 may be the sole cooling me dium, or there may be any number of auxiliary cooling mediums.

Reflux from the fractionating tower 15 may be removed through the line 32, in which may be interposed valve pump 33, which line 32 merges with the lines 26 and 28. All or any regulated portion 01 the reflux passing down through the line 32 may be passed into the lines 26 and 28, or all or any regulated amount of such reflux from line 32 may be diverted into the line 34, controlled by valve 35, and charged into the upper end of the dephlegmator 13, as illustrated.

Referring now to one of the features of the present invention, the reflux assing through the lines 26 and 28 may be c arged to a coil 36 mounted in a furnace 37, from which coil the heated reflux passes by way of transfer line 38, controlled by valve 39, and may enter the flash chamber either at the top or botton, through manipulation of the valves 39' and 39". Unvaporized residue may be withdrawn from chamber 10 through the drawod 40, controlled by valve 41.

In operation, raw oil is passed through the heating coil 6 wherein it israised, in its travel therethrough, to a conversion temperature under a suitable superatmospheric pressure. For instance, the temperature of the oil leaving coil 6 may be from 825 to 925 F, and the pressure may range from approximately 50 pounds to 500 pounds more or less. In passing through the transfer line 8, the pressure previously maintained on the heated oil is materially reduced or released altogether by proper manipulation of the pressure reducing valve 9, whereby, upon being discharged into the flash chamber 10, a large amount of vaporization will take place due to such pressure reduction and the release of latent heat contained therein. The extent of vaporization is adirect result of the amount of pressure reduction and the temperature 35 and pressure conditions maintained on the coil 6. Conditions in the dephlegmator 13 are so controlled as to condense all vapors which have a boiling point of approximately 550 ll, while the temperature conditions in the fractionating tower 15 are so controlled as to condense all vapors having a boiling point of approximately 450 F.

The ratio of reflux withdrawn from either or both of the lines 23 and 32 and passed through the coil 36, and the ratio 01 reflux returned for retreatment in the heating coil 6 will, of course, vary with different operations. The-amount of reflux passed through the high pressure coil 6 is determined by that necessary to condition the oil passing through the coil 6 to avoid coking; that is, it is intended that only a minimum amount of reflux be returned to the coil 6 for reheating and only that amount as is necessary to condition the oil passing through coil 6 to avoid objectionable coking, it being referable in the present operation to divert a maximum quantity of reflux to be separately heated in the coil 36. a,

The reflux passing through the coil 36 will be maintained under those conditions of super-atmospheric pressure and temperature determined to be most suitable to secure eflicient conversion of the reflux in the coil 36. Generally, the temperature in the coil 36 will be higher than in the coil 6. This temperature .mayeven be such that the so-called high temperature conversion Will occur, thus producing the maximum yields of aromatic, unsaturated naphthene and other desirable antikriock hydrocarbons. The proper temperatures and pressures to be maintained on the coil 36 are well Within the purview of those skilled in the art, having in mind that they shall be such as will produce the desired con- Version without excessive formation of coke and gas.

As a feature of the invention, the heated reflux from the coil 6 is passed through the line 38 and discharged into the flash chamber 10. While passing through line 38, the pressure is reduced or released altogether by proper manipulation of valve 39 so as to secure vaporization of said reflux in the flash chamber 10.

While we have shown the use of a dephlegmator l3 and a fractionating tower 15, 1t is, of course, to be understood that the operation contemplates the use of one, two or any number of dephlegmators or fractionating towers.

The purpose of the present invention is to separately treat the low boiling hydrocarbon products of the primary conversion which are not within the gasoline boiling range under conditions of temperature and pressure most suitable for the conversion of these relatively low boiling hydrocarbons.

Another purpose of the present invention is to eliminate expensive high pressure equipment, such as reaction chambers, dephlegrnaremove? ture. Hence, it is obvious that separate treatment of these unlike materials will give the best conditions of conversion with the minimum coke and gas formation. Further,

as stated, it may be desirable to convert the clean reflux oil into hydrocarbon suitable for anti-knock motor fuel, and this may best be done in a separate coil with conditions especially suited for this conversion which, if applied to coil 6, might cause excessive formation of coke and gas.

The operation may be carried out in such a manner as to withdraw either a liquid, semiliquid, semi-solid or solid residue from the chamber 10, controlled mainly by the temperature to which the reflux passing throu h the coil 36 is heated. According to United tates patent to C. P. Dubbs, No. 1,551,090, patented August 25,1925, the conditionsof operation are so cont-rolled as to produce two main products, vapors and a substantially solid residue, with an incidental production of incondensable gas. The present invention may be likewise operated so as to produce two main products, vapors and a substantially solid residue. As an advantage of the present invention, in such a process, the solid residue would be substantially decreased in amount over an operation in which such solid residue is produced in a chamber maintained -under substantial super-atmospheric pressure.

WPfClfllIll as our lnventlon: I lmA hydrocarbon o l cracking process which comprises subjecting the oil to crack- 1 ing conditions of temperature and superatmospheric pressure in a heating zone, subsequently reducing the pressure on the hot oil in a flashing zone to eflect vaporization thereof, dephlegmating the evolved vapors thereby forming reflux condensate, combining a portion of said reflux condensate with the oil being subjected to cracking conditions'in said heating zone, passing another portion of said reflux condensate to a second heating zone independent of the first mentioned heating zone and there subjecting the same to cracking conditions of temperature and pressure,

and discharging the heated reflux condensate from said second heating zone directly into said flashin zone.

2. A by rocarbon oil cracking processwhich comprises subjecting the oil to crackmg condltions of temperature and superatmospherlc pressure 1n a heating zone,

discharging the heated oil into a vapor separating zone, removing vapors from sald vapor separating zone and subjecting the same to primary and secondary dephlegmation thereby forming primary and second- .ary reflux condensates, combining at least a 3. A hydrocarbon oil cracking process which comprises subjecting the oil to crack.- ing conditions of temperature and superatmospheric pressure in a heating zone, subsequently reducing the pressure on the hot oil in a flashing zone to effect vaporization thereof, removing evolved vapors and subjecting the same to primary and secondary dephlegmation thereby forming primary and secondary reflux condensates, combining at least a portion of saidprimary reflux condensate with the oil being subjected to cracking conditions in said heating zone, passing said secondary reflux condensate to a second heating zone independent of the first mentioned heating zone and there subjecting the same to cracking conditions of temperature, and pressure, and then passing said secondary re- -flux condensate directly to said flashing zone without passage through said first mentioned @HSGLAHMEFE 1,810,673.Jacque O. Morrell and Warren F. Faragher, Chicago, Ill. HYDROCARBON 01L CONVERSION. Patent dated June 16, 1931. Disclaimer filed March 28,

1932, by the assignee, Universal 0%] Products Company.

Hereby disclaim from the scope of claim 2 of said Letters Patent any and all processes of cracking hydrocarbon oils, except such processes in which all unvaporized residual oil in the vaporizing zone is withdrawn therefrom and not again subjected to cracking conditions of temperature and superatmospheric pressure in the heating zone of the process.

(Oficial Gazette April 26, 1.932.) 

